Control device of a hybrid vehicle and method for operating same

A method of operating a hybrid vehicle having a hybrid drive unit that comprises an internal combustion engine and an electric machine, a clutch connected between the internal combustion engine and the electric machine and either an automatic or an automated transmission, and a control device that communicates with the transmission, the clutch and at least one of an engine temperature sensor, an electric machine temperature sensor and a further temperature sensor, the method comprising the steps of:

• stopping driving of the hybrid vehicle and terminating running of the internal combustion engine,
• when the hybrid vehicle becomes stationary and the internal combustion engine stops running, automatically determining, with the control device, an engine starting mode for a subsequent re-starting of the internal combustion engine, the determined engine starting mode is either a direct start by the electric machine, an impulse start by the electric machine or a start by a starter motor, based on a temperature of the electric machine, and a state of charge of an energy accumulator that communicates with the starter motor,
• automatically changing, with the control device, at least the transmission and the clutch, connected between the internal combustion engine and the electric machine, to a condition appropriate for the determined engine starting mode, and the transmission and the clutch being automatically changed to the condition appropriate for the determined engine starting mode either at a same time as or immediately after automatically determining the engine starting mode for the internal combustion engine and prior to an event that initiates the re-starting of the internal combustion engine, and the clutch being changed so as to be either completely disengaged or completely engaged depending on the determined engine starting mode,
• recognizing the event that initiates the re-starting of the internal combustion engine, subsequent to the automatic changing of at least the transmission and the clutch to the condition appropriate for the determined engine starting mode, and
• initiating the re-starting of the internal combustion engine according to determined engine starting mode.

A method of operating a hybrid vehicle having a hybrid drive unit which has a drive-train including a hybrid drive unit (1) with an internal combustion engine (2) and an electric machine (3), a first clutch (6) is connected between the internal combustion engine (2) and the electric machine (3) and either an automatic or an automated transmission (5) is connected between the hybrid drive unit (1) and a drive output (4), and a control device that communicates with the transmission, the first clutch and at least one of an engine temperature sensor, an electric temperature sensor and a further temperature sensor, the method comprising the steps of:

• terminating running of the internal combustion engine and bringing the hybrid vehicle to a stop;
• automatically selecting, with the control device (11), an engine starting mode from engine starting modes consisting of a direct start by the electric machine, an impulse start by the electric machine and a start by a starter motor when the hybrid vehicle becomes stationary and immediately after the internal combustion engine (2) stops running, and the determined engine starting mode being used for subsequent re-starting of the internal combustion engine (2);
• selecting the engine starting mode based on at least one of a temperature of the electric machine and a state of charge of an energy accumulator that communicates with the starter motor;
• automatically adjusting, with the control device, at least the transmission (5) and the first clutch (6) operating conditions that are appropriate for implementing the determined engine starting mode by emitting, via the control device (11), appropriate control signals to at least the transmission (5) and the first clutch (6), at least the transmission and the first clutch operating conditions being automatically adjusted before the subsequent re-starting of the internal combustion engine is initiated, such that the first clutch is either fully disengaged or fully engaged depending on the determined engine starting mode;
• and
• initiating the subsequent re-starting of the internal combustion engine, according to the determined engine starting mode, following the automatic adjustment of at least the transmission and the first clutch operating conditions.